David and Mike Calvin board a ship in search of several crates that contain 'wreckage' that rained down from the sky - the pieces of a crashed saucer! But the crates are gone; the aliens got to them first. The aliens also took a large shipment of heroin destined for 'The Organization' - an organized crime ring run by Peter Kalter. Kalter wants his shipment back and he's willing to kill to get it. But if David can convince him that the Invaders are here, he might gain a powerful, if ruthless and unpredictable, ally. On the other hand, others in the Organization simply want their drugs back, even if they have to sell out the human race to get them.